Write CL description into a temporary file

Also add open_text_tempfile() to FileSystem and its mock.

Bug: 780055
Change-Id: Ib6083639ab3774b468d6b6dc1cb41d818a1b0651
Reviewed-on: https://chromium-review.googlesource.com/747522Reviewed-by: Quinten Yearsley <qyearsley@chromium.org>
Commit-Queue: Robert Ma <robertma@chromium.org>
Cr-Commit-Position: refs/heads/master@{#512945}

third_party/WebKit/Tools/Scripts/webkitpy/common/system/filesystem.py

@@ -194,7 +194,7 @@ class FileSystem(object):
     def normpath(self, path):
         return os.path.normpath(path)
 
-    def open_binary_tempfile(self, suffix):
+    def open_binary_tempfile(self, suffix=''):
         """Create, open, and return a binary temp file. Returns a tuple of the file and the name."""
         temp_fd, temp_name = tempfile.mkstemp(suffix)
         f = os.fdopen(temp_fd, 'wb')
@@ -215,6 +215,12 @@ class FileSystem(object):
         with file(path, 'wb') as f:
             f.write(contents)
 
+    def open_text_tempfile(self, suffix=''):
+        """Create, open, and return a text temp file. Returns a tuple of the file and the name."""
+        _, temp_name = tempfile.mkstemp(suffix)
+        f = codecs.open(temp_name, 'w', 'utf8')
+        return f, temp_name
+
     def open_text_file_for_reading(self, path):
         # Note: There appears to be an issue with the returned file objects
         # not being seekable. See

third_party/WebKit/Tools/Scripts/webkitpy/common/system/filesystem_mock.py

@@ -337,6 +337,10 @@ class MockFileSystem(object):
         self.files[path] = contents
         self.written_files[path] = contents
 
+    def open_text_tempfile(self, suffix=''):
+        path = self.mktemp(suffix)
+        return (WritableTextFileObject(self, path), path)
+
     def open_text_file_for_reading(self, path):
         if self.files[path] is None:
             self._raise_not_found(path)

third_party/WebKit/Tools/Scripts/webkitpy/w3c/test_importer.py

@@ -433,17 +433,24 @@ class TestImporter(object):
         directory_owners = self.get_directory_owners()
         description = self._cl_description(directory_owners)
         sheriff_email = self.tbr_reviewer()
+
+        temp_file, temp_path = self.fs.open_text_tempfile()
+        temp_file.write(description)
+        temp_file.close()
+
         self.git_cl.run([
             'upload',
             '-f',
             '--gerrit',
-            '-m', description,
+            '--message-file', temp_path,
             '--tbrs', sheriff_email,
             # Note: we used to CC all the directory owners, but have stopped
             # in search of a better notification mechanism. (crbug.com/765334)
             '--cc', 'robertma@chromium.org',
         ])
 
+        self.fs.remove(temp_path)
+
     def get_directory_owners(self):
         """Returns a mapping of email addresses to owners of changed tests."""
         _log.info('Gathering directory owners emails to CC.')